JP5515118B2 - Plant growth facility - Google Patents

Description

  The present invention relates to a plant growing facility. More specifically, the present invention relates to a plant growth facility that performs carbon dioxide application to increase yield and improve quality by increasing the amount of photosynthesis by giving carbon dioxide to plants such as tomato, cucumber, eggplant, and paprika.

  In recent years, abnormal weather has occurred worldwide, and it is feared that it will affect the production of plants. For this reason, the spread of the plant factory which can grow vegetables etc. regardless of the weather is desired.

  As a plant factory, on the basis of the use of sunlight, “solar light utilization type” facilities have been developed that produce plants in a semi-closed environment such as a glass greenhouse. The solar-powered plant factory is positioned as a development of traditional horticulture using greenhouses, and measures both environmental information and biological information of the plant being cultivated, and controls the environment based on it. Has an advanced environmental control system. For example, in Northern Europe, there is a season in which the sunshine hours are very short, so an artificial light source is installed in a “solar-powered” facility to compensate for the lack of sunlight. Production has been done for a long time, and based on that, advanced horticulture using plant factories has been developed in various parts of Europe such as the Netherlands.

In plant factories such as those described above, plants are shielded from the outside air by an outer shell (covering material) such as a greenhouse, so that the amount of carbon dioxide may become insufficient during the day when photosynthesis is actively performed. If the amount of carbon dioxide is insufficient, sufficient photosynthesis may not occur and the plant may not develop sufficiently. To prevent the amount of carbon dioxide from being insufficient, artificially give carbon dioxide to the plant. Is performed. In addition, if the carbon dioxide concentration in the greenhouse is made higher than the carbon dioxide concentration in the atmosphere by this carbon dioxide application, the photosynthesis of the plants can be made more active, and the yield can be increased.
For example, by supplying carbon dioxide from an air duct that extends inside a greenhouse, etc., and increasing the concentration of carbon dioxide in the air inside the greenhouse, etc. A method of forming and adjusting each space to an optimum carbon dioxide concentration (Patent Document 1), a method of applying carbonated water to a plant body and applying carbon dioxide (Patent Document 2), and the like have been developed.

By the way, compared with the countries such as Scandinavia, the plant factory becomes hot in the daytime on a fine day in Japan and the like over a long period from spring to autumn. If the temperature in the plant factory becomes too high, various growth defects such as sovereignty, poor flowering, and sterility occur in plant cultivation. In addition to these, there is an adverse effect such as an increase in the respiration rate of plants and the occurrence of physiologically impaired fruits, resulting in a decrease in yield.
For this reason, in order to maintain the temperature in the plant factory within a certain range, the skylight and the side window are opened, and exchange of air with the outside air, that is, ventilation is performed. By performing such ventilation, the heat in the plant factory can be discharged to the outside by exchanging the hot air in the plant factory and the low temperature outside air (hereinafter referred to as heat exchange).

However, although the air temperature in the plant factory can be controlled to some extent by such heat exchange, the air in the plant factory is exhausted, and thus gas exchange is performed simultaneously with the heat exchange. Then, since the carbon dioxide applied in the plant factory is also discharged outside the plant factory by ventilation, it is difficult to maintain the inside of the plant factory in a high carbon dioxide concentration environment.
Even in the technique of Patent Document 1, although it is divided into a plurality of spaces by curtains or the like, heat exchange in each space is performed through a ventilation window of the greenhouse. Therefore, when ventilation is performed, the dioxide dioxide applied to each space is used. Carbon is discharged outside the greenhouse through the ventilation window. For this reason, when ventilation is performed, it is difficult to maintain the environment in each space, that is, the environment around the plant in a high carbon dioxide concentration state, as in a conventional greenhouse.

  As described above, in an environment where the temperature in the plant factory becomes high, it is not always possible to maintain the environment around the plant in a high carbon dioxide concentration state while maintaining the temperature inside the plant factory at an appropriate temperature. It is difficult to develop facilities that can realize an environment that can maintain both conditions.

JP 2009-153405 A JP 2008-199920 A

  In view of the above circumstances, an object of the present invention is to provide a plant-growing facility that can maintain an environment for growing plants in an appropriate temperature and high carbon dioxide concentration in a facility that uses sunlight. .

The plant growth facility according to the first aspect of the present invention includes a greenhouse that uses sunlight, and a growth room that is provided in the greenhouse and that grows the plant in a state in which the plant is accommodated. A coating portion made of a light-transmitting member provided so as to surround the plant, and a carbon dioxide supply means disposed in the coating portion for supplying carbon dioxide into the coating portion, The covering portion is provided with a ventilation portion for ventilating the air in the covering portion and the air in the greenhouse, and the humidity of the air in the covering portion is higher than the humidity of the air in the greenhouse. It is characterized by being kept high.
The plant growth facility according to a second aspect of the present invention is characterized in that, in the first aspect, the ventilation section is formed such that the number of ventilations in the growth room is less than the number of ventilations in the greenhouse.
In the plant growing facility according to the third aspect of the present invention, in the first or second aspect, the light transmissive member forming the covering portion has a structure capable of scattering the light irradiated on the covering portion. Features.
The plant growing facility according to a fourth aspect of the present invention is characterized in that, in the first, second or third aspect of the invention, a water spray means for spraying water droplets on the outer surface of the covering portion is provided in the greenhouse. And

According to the first invention, when carbon dioxide is supplied from the carbon dioxide supply means into the covering portion of the growth chamber, the carbon dioxide concentration of the air in the covering portion, that is, the carbon dioxide concentration in the vicinity of the plant is set to a high concentration state. Can do. In addition, since the covering portion is formed of a light-transmitting member, the plant housed in the covering portion of the growing room can be photosynthesized in a high carbon dioxide concentration state, thereby promoting plant growth and harvesting. The amount can be increased. And since the humidity of the air in a coating | coated part is higher than the humidity of the air of a greenhouse, when the coating | coated part is ventilated, the heat more than the heat supplied in a coating | coated part can be discharged | emitted outside. Therefore, even in summer when there is a large amount of solar radiation, the inside of the covering portion can be maintained at a temperature at which plants can grow.
According to the second invention, since the ventilation frequency of the covering portion is less than the ventilation frequency of the greenhouse, it is possible to suppress a decrease in the carbon dioxide concentration of the air in the covering portion, and the carbon dioxide gas directly against the greenhouse air. Compared with the case of supplying a high carbon dioxide concentration condition with a small amount of carbon dioxide application.
According to the 3rd invention, since the light irradiated to the coating | coated part of the growth room is scattered in a coating | coated part, light can be uniformly irradiated with respect to the whole plant body in a coating | coated part. In addition, light that does not enter the plant, such as light that is applied to the side surface of the covering portion, can be supplied to the plant by being scattered into the coating portion so that the plant can efficiently synthesize light. Can do.
According to the 4th invention, the air temperature of a coating | coated part can be reduced because the water droplet sprayed on the outer surface of a coating | coated part evaporates.

It is a schematic explanatory drawing in the greenhouse 2 of the plant cultivation facility 1 of this embodiment. It is a single-unit schematic explanatory drawing of the cultivation room 10, Comprising: (A) is a longitudinal cross-sectional view, (B) is a partial side view. It is a schematic external view of the greenhouse 2 of the plant growth facility 1 of the present embodiment. It is the figure which showed the experimental result which investigated the ventilation characteristic of the growth room. It is the figure which showed the experimental result which investigated the state of the air of a growth room and the state of the air of a greenhouse in winter. It is the figure which showed the experimental result which investigated the state of the air of a growth room and the state of the air of a greenhouse in summer. It is the figure which showed the experimental result which investigated the photosynthesis property of the plant in high carbon dioxide concentration conditions.

Next, an embodiment of the present invention will be described with reference to the drawings.
The plant growing facility of the present invention is a facility that grows plants using sunlight and applying carbon dioxide, and even in a period when the amount of heat supplied by sunlight in the facility is large. It is characterized in that the inside of the facility can be maintained at a high carbon dioxide concentration condition while maintaining the temperature of the plant at a temperature at which plants can be grown.

(Explanation of plant growth facilities)
As shown in FIG. 1, the plant growth facility 1 of the present embodiment includes a greenhouse 2 provided outdoors and a growth room 10 provided in the greenhouse 2.

(Description of greenhouse 2)
First, as shown in FIG. 3, the greenhouse 2 is a general greenhouse used for plant cultivation, such as a building in which walls and roofs are formed of glass, vinyl, or the like. The greenhouse 2 is provided with a skylight 2a, windows, and the like. By opening and closing these, the air inside the greenhouse 2 and the outside air can be ventilated.
The number of ventilations of the greenhouse 2 depends on the size of the greenhouse 2 itself, the size of the skylight 2a, the opening of the skylight 2a, the temperature inside and outside the greenhouse, the wind speed and the direction of the wind, etc., but about 50 to 100 per hour at the maximum. About times.

(Explanation of training room 10)
As shown in FIG. 1, a plurality of growing rooms 10 are provided in the greenhouse 2. The growing room 10 includes a covering portion 11 having a space 10 h for cultivating the plant P therein, and carbon dioxide supply means for supplying carbon dioxide into the covering portion 11.

First, the covering portion 11 is a structure extending in the depth direction having a hollow space 10h (in FIG. 1, a direction orthogonal to the paper surface, hereinafter referred to as the axial direction of the growth chamber 10).
The covering portion 11 is a sheet-like member made of a material that does not transmit air but transmits light (for example, an agricultural polyvinyl chloride film or an agricultural polyolefin-based film, hereinafter simply referred to as a light-transmitting member). Is formed by.
The covering portion 11 is provided with a ventilation portion for performing so-called ventilation in which the air in the space 10h surrounded by the covering portion 11 is replaced with the air in the greenhouse 2.
In other words, the covering portion 11 keeps the internal space 10h between the space 10h and the space in the greenhouse 2 through the ventilation portion while keeping the internal space 10h isolated from the outside (that is, the space in the greenhouse 2) to a certain extent. It is configured to allow gas exchange.
The ventilation section is not particularly limited as long as the air in the space 10 h can be replaced with the air in the greenhouse 2. For example, a gap formed at the joint of the sheets constituting the covering section 11, a sheet It can comprise by the through-hole etc. which were provided in.

A cultivation bed 14 extending along the axial direction is provided in the space 10h in the covering portion 11 of the growth chamber 10. The cultivation bed 14 is installed in a state of being suspended in the space 10h in the cultivation room 10 by a wire (not shown) (that is, separated (floating) from the floor surface of the greenhouse 2). Plant P is cultivated in 14. That is, the plant P grows in the space 10 h in the growing room 10 so as to extend upward from the cultivation bed 14 in a state in which the root is in the cultivation bed 14.
In addition, piping for supplying fertilizer (for example, liquid fertilizer), water, etc. with respect to the cultivation bed 14 in the space 10h in the cultivation room 10 is provided in the plant P, and fertilizer and water are suitably used. It can be supplied to the plant P.

  As shown in FIGS. 1 and 2, the space 10 h in the growth chamber 10 is provided with a carbon dioxide supply pipe 15 serving as a carbon dioxide supply means for supplying carbon dioxide into the growth chamber 10. The carbon dioxide supply pipe 15 is disposed along the axial direction of the growth chamber 10, and a carbon dioxide discharge section 15 a for discharging carbon dioxide from the carbon dioxide supply pipe 15 is provided at an appropriate position in the axial direction. (See FIG. 2B).

As described above, in the plant growing facility 1 of the present embodiment, since the covering portion 11 is composed of a sheet formed of a light transmissive member, the covering portion 11 is transmitted through the plant P in the space 10h. Sunlight can be irradiated. That is, even if the plant P is cultivated in a state of being accommodated in the space 10h surrounded by the covering portion 11 of the growing room 10, the plant P can be photosynthesised.
In addition, a carbon dioxide supply pipe 15 is disposed in a space 10h surrounded by the covering portion 11 of the growth chamber 10, and a carbon dioxide discharge section 15a provided in the carbon dioxide supply pipe 15 enters the space 10h. Carbon dioxide can be supplied. For this reason, the carbon dioxide concentration in the space 10h, that is, the carbon dioxide concentration of air in the vicinity of the plant P can be set to a high concentration state. Specifically, the carbon dioxide concentration in the vicinity of the plant P can be made higher than the carbon dioxide concentration in the atmosphere or in the space inside the greenhouse 2 outside the growth room 10.
Then, in the plant growth facility 1 of the present embodiment, the plant P can be photosynthesisd in a state with a high carbon dioxide concentration in the space 10h surrounded by the covering portion 11 of the growth room 10, so that the plant P Photosynthesis can be maintained in an active state.

  Therefore, when the plant P is cultivated in the plant cultivation facility 1 of the present embodiment, the plant P is cultivated in normal outdoor cultivation or in a greenhouse, or while applying carbon dioxide in a general greenhouse. Compared with the case where P is cultivated, the growth of the plant P can be promoted.

(Continuous breeding of plant P at high carbon dioxide concentration)
Moreover, when the plant P is continuously grown in a situation where the concentration of carbon dioxide is high, when carbon dioxide is applied, compared to a case where carbon dioxide is applied spotly to a plant cultivated in a general environment. The photosynthesis ability of can be increased.
Therefore, if the plant P is continuously cultivated in the plant growth facility 1 of the present embodiment, the photosynthetic ability of the plant P when carbon dioxide is applied can be increased. Therefore, the plant P is cultivated while applying carbon dioxide. By this, the growth of the plant P can be further promoted.

(Development based on SPA concept)
In particular, a carbon dioxide concentration meter, a light intensity meter for measuring light intensity, a hygrometer, a thermometer, etc. are provided in the space 10h, and the amount of carbon dioxide supplied into the space 10h based on these measured values. If carbon dioxide is adjusted, carbon dioxide can be applied efficiently, and the plant P can be grown efficiently.
For example, the above-described measuring instrument is provided, and a carbon dioxide supply means and a means for automatically supplying fertilizer and water to the cultivation bed 14 are provided, and the operation of the carbon dioxide supply means and the like is performed based on the measurement value of the measuring instrument. A control device for controlling the above is provided. And the control apparatus records the data etc. which show the relationship between the photosynthetic ability of the plant P to be cultivated estimated based on the biological information measured in advance and the appropriate environment information for exerting the ability. . Then, by operating the carbon dioxide supply means, etc., the control device supplies an appropriate amount of carbon dioxide into the space 10h corresponding to environmental information (light intensity, temperature, humidity, etc.) measured in real time. Can do. That is, since the carbon dioxide application based on the Speaking Plant Approach (SPA) concept can be performed in the space 10h, the plant P can be grown more efficiently. In particular, when the volume of the space 10h is small (for example, about 40% of the entire conventional greenhouse), the time constant until the set carbon dioxide concentration is reached after the carbon dioxide concentration is supplied becomes small. Then, the carbon dioxide concentration control which follows the sunlight intensity which changes every moment is also attained. Specifically, the amount of carbon dioxide input can be temporarily reduced when the light is temporarily weakened by a cloud or the like.

(Description of each part)
For example, a nozzle or a hole provided in the carbon dioxide supply pipe 15 can be used for the carbon dioxide discharge part 15a described above, but from the carbon dioxide supply pipe 15 to the space 10h in the growth chamber 10. There is no particular limitation as long as it has a mechanism capable of discharging carbon dioxide.
Further, the method for supplying carbon dioxide to the carbon dioxide supply pipe 15 is not particularly limited. For example, if the cylinder filled with carbon dioxide and the carbon dioxide supply pipe 15 are connected by a control valve, a flow meter, or the like, the supply of carbon dioxide can be stopped or the carbon dioxide can be operated by operating the control valve, the flow meter, or the like. Carbon supply can be adjusted manually or automatically.
Furthermore, a means for automatically supplying fertilizer and water to the cultivation bed 14 is not particularly limited. For example, if it is set as the structure which connected the piping provided in the cultivation bed 14 and the water pipe by the control valve, the flow meter, etc., the supply stop and supply amount of fertilizer and water will be carried out by operating the control valve, the flow meter, etc. Can be adjusted manually or automatically. Of course, it goes without saying that the amount of fertilizer and water supplied to the cultivation bed 14, the timing of supplying the fertilizer and water, and the like may be adjusted by manually operating the control valve and the like.

(About the material of the sheet | seat of the coating | coated part 11)
Moreover, the material of the sheet | seat of the coating | coated part 11 will not be specifically limited if it is a light transmissive member, However, As a material of a sheet | seat, what has the structure which can permeate | transmit and scatter the light irradiated to the surface. preferable.
When the covering portion 11 is formed by such a sheet, the light irradiated to the covering portion 11 is transmitted through the sheet and scattered, so that light of almost uniform intensity can be applied to any part of the plant in the covering portion 11. . For example, in one leaf, the difference depending on the location of the intensity of irradiated light can be reduced.
Moreover, the light or the like irradiated to the position of the side surface of the covering portion 11 is light that reaches the floor surface of the greenhouse 2 without being irradiated to the plant P when the covering portion 11 is absent. Due to the presence of the covering portion 11, the light can also be incident on the plant P by being converted into scattered light by the covering portion 11.

  In addition, when it is set as the coating | coated part 11 as mentioned above, depending on the location of a leaf, the part in which the light intensity irradiated partly becomes weak compared with the case where the coating | coated part 11 is not provided, and the photosynthesis amount of the part is a coating | coated part. Compared with the case where 11 is not provided. However, in the portion where the light intensity irradiated when there is no covering portion 11 as described above is high, the light intensity irradiated on that portion becomes strong, and when there is no covering portion 11, almost no light is emitted. You can also shine light on the part that was not hit. For this reason, the amount of photosynthesis of the portion where the amount of photosynthesis was small can be increased, and the portion where photosynthesis has hardly been performed can also be photosynthesised, so that the amount of photosynthesis of the entire plant P can be increased.

Examples of the material of the sheet that exhibits such an effect include a light-transmitting member having a satin finish, but any material that exhibits the above effect may be used, and the material of the sheet is not particularly limited.
Moreover, in using the light which was not originally irradiated to the plant P by scattering the light incident on the sheet material, the side surface of the covering portion 11, that is, the portion located on the side of the plant P in the covering portion 11. A larger area is preferable. This is because the light passing through the side of the plant P is unlikely to be irradiated to the plant.
In consideration of the fact that the plant P generally tends to extend upward, if the covering portion 11 has a shape that is long in the vertical direction, the use efficiency of light scattered by the covering portion 11 is increased. I think you can.

(Temperature maintenance)
By the way, in the greenhouse 2, the air flow between the inside and the outside is restricted, and the air in the greenhouse 2 is held in the greenhouse 2 for a certain period of time. For this reason, since the temperature of the greenhouse 2 becomes higher than the temperature of the outside air due to the thermal energy of sunlight irradiated to the greenhouse 2, the temperature in the greenhouse 2 may rise to a temperature unsuitable for cultivation of the plant P. There is. For this reason, in the general greenhouse 2, the temperature is adjusted by opening and closing the skylight 2a and performing ventilation so that the temperature of the greenhouse 2 does not rise too much. For example, the greenhouse 2 is adjusted so that the temperature inside the greenhouse 2 becomes approximately the same as the temperature of the outside air (for example, about ± 5 degrees of the temperature of the outside air) by performing ventilation.

In the plant growing facility 1 of the present embodiment, a plurality of growing rooms 10 are provided in the greenhouse 2, and the plant P is cultivated in a space 10 h surrounded by the covering portion 11 of the growing room 10. Although the covering portion 11 of the growing chamber 10 is also provided with a ventilation portion that ventilates the air in the space 10h surrounded by the covering portion 11, there is a possibility that the temperature of the space 10h cannot be lowered. For example, when the amount of heat supplied by sunlight is large, for example, in summer, the temperature of the space 10h may not be lowered even if the temperature of the greenhouse 2 can be adjusted to the same level as the temperature of the outside air. . That is, the air temperature in the space 10h may rise to a temperature that is not suitable for plant P cultivation.
In this case, it is considered that the temperature of the space 10h can be lowered to the same level as the temperature of the greenhouse 2 by opening the covering part 11 widely and increasing the ventilation frequency of the space 10h. Carbon dioxide also escapes into the greenhouse 2, making it difficult to maintain a high concentration of carbon dioxide in the space 10h.

However, in the plant growing facility 1 of the present embodiment, the humidity of the air in the space 10 h is maintained higher than the humidity of the air in the greenhouse 2. For this reason, even if it does not enlarge the frequency | count of ventilation of the space 10h, it can prevent that the temperature of the space 10h rises to the temperature where the plant P cannot grow. That is, the air in the space 10h can be maintained at a high carbon dioxide concentration while maintaining the temperature in the space 10h at a temperature at which the plant P can grow.
The reason is as follows.

First, when the air in the space 10h and the air in the greenhouse 2 are ventilated, the flow rate of the air discharged from the space 10h into the greenhouse 2 (hereinafter referred to as exhausted air) and the air flowing into the space 10h from the greenhouse 2 (hereinafter referred to as If the temperature and absolute humidity of the inflow air and the exhaust air are not the same, strictly speaking, the volume of the inflow air and the exhaust air is different, but strictly speaking, they are so large. No difference).
Then, if the humidity of the air in the space 10h is higher than the humidity of the air in the greenhouse 2, if the temperature of both is the same, the amount of heat that is brought into the space 10h by the inflowing air will be larger than that in the space 10h by the exhausted air. The amount of exhaust heat that is taken away from the plant becomes larger.
Further, since transpiration from the plant P and other water evaporation occur, the heat energy of the space 10h is consumed even when the water is vaporized. Note that transpiration from the plant P and evaporation of other water also contribute to an increase in the humidity of the air in the space 10h.

Then, if the difference between the inflow heat amount and the exhaust heat amount and the total heat of vaporization is greater than or equal to the amount of heat supplied to the space 10h by sunlight, the air temperature in the space 10h is changed to the air in the greenhouse 2. It can be maintained at almost the same temperature.
Moreover, since the frequency of air ventilation in the space 10h is kept low, the carbon dioxide concentration in the air in the space 10h can be kept high while maintaining the temperature in the space 10h at a temperature suitable for growing the plant P. It is.

In order to maintain the temperature of the space 10h according to the above principle, it is necessary to maintain the humidity of the air in the space 10h higher than the humidity of the air in the greenhouse 2.
As described above, the humidity of the air in the space 10h can be kept higher than the humidity of the air in the greenhouse 2 only by transpiration from the plant P cultivated in the space 10h or evaporation of other water. it can.
However, if the plant P is a small individual, such as immediately after the start of cultivation, and the amount of transpiration from it is insufficient to increase the humidity of the air in the space 10h, the transpiration from the plant P alone, In some cases, the humidity of the air in the space 10 h cannot be maintained higher than the humidity of the air in the greenhouse 2.
Therefore, even in such a case, if the humidity of the air in the space 10h is maintained higher than the humidity of the air in the greenhouse 2, a humidity adjusting means for adjusting the humidity of the air in the space 10h should be provided in the space 10h. Is preferred.

For example, if a device having a function of spraying water in the space 10h is provided as the humidity adjusting means, the humidity of the air in the space 10h can be maintained higher than the humidity of the air in the greenhouse 2.
In particular, if the number of ventilations in the space 10h is known, the optimal heat exchange can be achieved by measuring the temperature in the greenhouse 2, the temperature in the space 10h, and the amount of solar radiation incident on the space 10h. It is also possible to adjust the humidity of the space 10h by the humidity adjusting means.

  As described above, since the space 10h is separated to some extent from the inside of the greenhouse 2 by the covering portion 11, the humidity of the air in the space 10h is usually inside the greenhouse 2 by transpiration from the plant P cultivated in the space 10h. The air humidity is maintained higher than the humidity. Therefore, if the humidity of the air in the space 10h can be maintained to such an extent that the temperature can be maintained based on the above principle in the cultivation state of the normal plant P, the humidity adjustment by the humidity adjusting means may not be performed. It is not necessary to provide a simple humidity adjusting means. However, if the humidity adjusting means is provided, there is an advantage that the degree of freedom in adjusting the humidity of the air in the space 10h, in other words, the temperature adjustment in the space 10h is increased.

(Explanation of water spraying means)
If it is difficult to reduce the temperature of the space 10h to a temperature at which the plant P can grow only by maintaining the temperature based on the above principle, the temperature in the greenhouse 2 can be increased with respect to the outer surface of the covering portion 11. It is preferable to provide a water spraying means for spraying water droplets. Specifically, it is preferable to provide, for example, a nozzle or the like that can spray water droplets on the ceiling or wall surface of the greenhouse 2 against the outer surface of the covering portion 11.
If such water spraying means is provided, the coating portion 11 itself is cooled by the heat of vaporization of water adhering to the surface of the coating portion 11, and the space 10 h in contact with the inside of the coating portion 11 through the coating portion 11. The temperature of the space 10h can be lowered by directly taking the heat of the air.

In addition, in order to obtain the cooling effect by water spray as described above, it is preferable that the surface area of the covering portion 11 is sufficiently large. Considering that the plant P is generally extended upward, it is considered that the cooling effect by water spray can be enhanced if the covering portion 11 has a long shape in the vertical direction.
However, if the humidity of the air in the greenhouse 2 increases due to this water spray, the efficiency of exhaust heat due to ventilation in the space 10h will decrease. Adjusted.

(Description of the covering portion 11)
In particular, the covering portion 11 has a structure in which the ventilation frequency of the space 10h is about 1/10 to 1/5 of the ventilation frequency of the greenhouse 2, that is, about 5 to 20 times per hour. What has is preferable.
When the number of ventilations in the space 10h is less than 5 times per hour, the temperature in the space 10h cannot be sufficiently lowered under the condition that the amount of heat supplied by sunlight is large. In such a case, a facility for cooling the air in the space 10h using electric energy or the like is required.
On the other hand, when the ventilation frequency is more than 20 per hour, even if the amount of carbon dioxide supplied to the space 10h is increased, it is difficult to maintain a high carbon dioxide concentration in the air in the space 10h.
Therefore, in order to exhibit the function of adjusting the temperature of the space 10h by ventilation while maintaining a high carbon dioxide concentration in the air of the space 10h, the number of ventilations in the space 10h is preferably 5 to 20 times per hour. .

  The ventilation frequency can be measured by a known method. For example, the CO2 tracer method that estimates the number of ventilations based on changes in CO2 gas concentration, the amount of inflow heat (sunlight, inflow heat due to ventilation, inflow heat from the ground), and the room temperature and humidity are measured Thus, the ventilation frequency can be estimated by a heat balance method for estimating the ventilation frequency.

Examples of the covering portion 11 that satisfies the above conditions include those having a structure having an upper covering portion 13 and a lower covering portion 12 as follows.
Hereinafter, the covering portion 11 having the upper covering portion 13 and the lower covering portion 12 will be described.

  As shown in FIG. 2, the covering portion 11 includes a lower covering portion 12 formed in a U shape in a sectional view and an upper covering portion 13 provided above the lower covering portion 12.

(Description of the upper covering portion 13)
The upper covering portion 13 is composed of an upper sheet 13a and a pair of end sheets 13b and 13b.

  The upper sheet 13a is a sheet material formed of a light-transmitting material, and is hung on three wires (or pipes) W1 to W3 that are horizontally stretched on the ceiling of the greenhouse 2. The three wires W1 to W3 on which the upper sheet 13a is hung are stretched along the axial direction of the growth chamber 10, and are arranged so that the central wire W2 is positioned higher than the other wires W1 and W3. Has been. For this reason, the upper sheet 13a is a roof whose center in the width direction (left and right in FIGS. 1 and 2A) is higher than the both ends by the wires W2, and both ends hang down from the wires W1 and W3. It becomes the shape of the mold.

  Further, the pair of end sheets 13b and 13b is a sheet material formed of the same material as the upper sheet 13a. The pair of end sheets 13b, 13b are provided at both ends of the upper sheet 13a in the axial direction of the growth chamber 10, and are provided so as to close the end of the upper sheet 13a.

Therefore, the upper covering portion 13 is formed with a space 13h having an opening in the lower portion surrounded by the upper sheet 13a and the pair of end sheets 13b and 13b.
In addition, without providing a pair of end part sheet | seats 13b and 13b, the edge part of the upper sheet | seat 13a is carried out by methods, such as hanging down the both ends of the axial direction of the growth chamber 10 in the upper sheet | seat 13a, or connecting an edge. Even if it is closed, the space 13h can be formed.

(Description of the lower covering portion 12)
The lower covering portion 12 is formed in a substantially U shape in sectional view by connecting the lower end portions of the pair of side sheets 12a and 12a.

  The pair of side sheets 12a, 12a is a sheet material formed of a light-transmitting material. The pair of side sheets 12a and 12a are attached to two wires (or pipes) W4 and W5 whose upper ends are horizontally stretched on the ceiling of the greenhouse 2, and hang downward from the upper ends. It is provided so that it may be in the state.

  The two wires W4 and W5 to which the pair of side sheets 12a and 12a are attached are stretched along the axial direction of the growth chamber 10, and in the horizontal direction, the wire W4 is between the wires W1 and W2. Moreover, the wire W5 is arrange | positioned so that it may each be located between the wire W2 and the wire W3. And two wires W4 and W5 are installed so that both may be located in the upper sheet | seat 13a above the lower end of the both ends which hung down from the wires W1 and W3. For this reason, the pair of side sheets 12a, 12a is installed so that the upper ends thereof are located in the space 13h formed by the upper covering portion 13.

  Moreover, as for a pair of side sheet | seat 12a, 12a, the length of the perpendicular direction is longer than the distance from the two wires W4 and W5 to the lower end of the cultivation bed 14, and both lower ends are cultivation beds 14 It is connected below. Note that the lower ends of the pair of side sheets 12a and 12a are connected so as not to be airtight, and the reason will be described later.

  And a pair of side sheet | seat 12a, 12a is mutually connected by the axial direction both ends of the growth chamber 10 so that the opening between both both ends may be plugged up.

Since it is the shape as described above, the lower covering portion 12 is surrounded by a pair of side sheets 12a, 12a, has an opening at the upper end, and the opening is covered by the upper covering portion 13 to be cultivated plant P Thus, a space 12h in which is placed is formed.
In addition, although the lower coating | coated part 12 has connected the both ends of a pair of side sheet 12a, 12a mutually, you may provide the edge part sheet | seat which connects the edge parts of a pair of side sheet 12a, 12a. It is sufficient that large openings are not formed at both ends of the pair of side sheets 12a and 12a.

(Effect of the whole covering part 11)
As described above, the covering portion 11 is formed so that the lower covering portion 12 and the upper covering portion 13 are shaped as described above and arranged as described above. While the space can be isolated, the air in the space 10h can be ventilated.

  Specifically, a gap (hereinafter referred to as an upper gap) is formed between the upper ends of the pair of side sheets 12a, 12a and both ends of the upper sheet 13a. A pair of side sheets 12a, 12a are connected so that the lower ends thereof are not airtight, and a gap (hereinafter referred to as a lower gap) is formed between the space 10h and the outside (inside the greenhouse 2). For this reason, the air in the space 10h can be discharged into the greenhouse 2 and the air in the greenhouse 2 can be allowed to flow into the space 10h through the lower gap and the upper gap.

In addition, since the total area of the upper gap and the lower gap is very small compared to the surface area of the covering portion 11 (for example, 1/100 or less), the space 10h is interposed through the lower gap and the upper gap. The flow rate of the air passing between the greenhouse 2 and the greenhouse 2 is smaller than the volume of the space 10h.
Therefore, the number of ventilations in the space 10h is less than the number of ventilations in the greenhouse 2, and preferably the number of ventilations in the space 10h can be about 5 to 20 times per hour.

In addition, the ratio of the said total area with respect to the surface area of the coating | coated part 11 is not restricted to the said range, What is necessary is just the grade which can maintain the ventilation frequency of the space 10h to about 5-20 times per hour.
In addition, there are gaps in the lower covering portion 12 and the upper covering portion 13 other than the upper gap and the lower gap, and ventilation through the gap is also performed. The gaps other than the upper gap and the lower gap are not particularly limited in the position and size of the gap as long as the ventilation frequency of the space 10h can be maintained in the above range. 11 may be formed so as not to have any gaps other than the upper gap and the lower gap.

  Since the space 10h is ventilated under the above conditions, the carbon dioxide concentration of the air in the space 10h can be kept high even if the air in the space 10h is ventilated, and the carbon dioxide supplied to the space 10h Even if the amount is reduced, the carbon dioxide concentration of the air in the space 10h can be increased. For example, even when the greenhouse 2 is actively ventilated with the skylight 2a fully open, the carbon dioxide concentration of the air in the space 10h can be maintained at 1000 ppm or more.

  Each side sheet 12a of the lower covering portion 12 may be formed by a single sheet, but may be formed by two or more sheets so that it can be opened and closed like a curtain (see FIG. 2 (B)). With such a structure, although the airtightness of the portion connecting the two sheets (the place where the connection and separation is possible) is lowered, there is an advantage that it is easy to care for the crop to be cultivated.

Moreover, the shape of the lower coating | coated part 12 is not limited to U shape, The air of the space 10h should just be isolated to some extent from the air in the greenhouse 2 by the coating | coated part 11. FIG. For example, the pair of side sheets 12a and 12a may be linearly extended so that the lower ends thereof are in contact with the floor surface of the greenhouse 2.
When the pair of side sheets 12a and 12a are provided as described above, it is preferable that each side sheet 12a be structured to be wound up from the lower end thereof. That is, each side sheet 12a may have a structure like a roll curtain. Then, if the pair of side sheets 12a, 12a is rolled up, the plant P in the covering portion 11 can be approached from the opening where the side sheets 12a are rolled up, so that it becomes easy to care for the crops to be cultivated. The advantage is obtained.
Similarly, both end portions in the width direction of the upper covering portion 13 may be wound up. In this case, if both ends are adjusted in the amount of winding, the advantage that the inflow / exhaust of air through the upper gap can be adjusted is obtained. That is, if the amount of winding is reduced (in other words, if the length overlapping with the side sheet 12a is increased), the inflow and discharge of air through the upper gap becomes difficult, and the number of ventilations can be reduced. On the contrary, if the amount of winding is increased (in other words, if the length overlapping the side sheet 12a is shortened), air can be easily introduced and discharged through the upper gap, and the number of ventilations can be increased.

  Furthermore, in the above example, the structure in which the end portions in the axial direction of the lower covering portion 12 and the upper covering portion 13 are closed by separate sheets or the like has been described. However, the end portions in the axial direction of the lower covering portion 12 and the upper covering portion 13 are described. May be closed by a single sheet. Specifically, if a sheet is provided that covers the axial end portion of the upper covering portion 13 from above the upper covering portion 13 and whose lower end extends to the lower end of the lower covering portion 12, The axial ends of the covering portion 12 and the upper covering portion 13 can be closed.

  In order to confirm the effectiveness of the plant growth facility of the present invention, (1) ventilation characteristics of the growth room, (2) carbon dioxide concentration maintenance capability in the growth room, (3) temperature maintenance function, (4) high carbon dioxide The photosynthetic ability of the plant under concentration conditions was confirmed.

  The equipment used for the experiment is as follows.

First, the greenhouse has a width of about 20 m, a height of about 5 m, and a depth of about 20 m (volume 20,000 m ³ ) with a glass-lined ceiling and an agricultural polyolefin film-sided side. In addition, the ventilation window for ventilation is provided on the ceiling, and the number of ventilations when this ventilation window is used is estimated to be about 50 to 100 times per hour at the maximum.
The growing room is formed with a space for cultivating a plant by the covering portion having the upper covering portion and the lower covering portion described above, and has a width of 1.2 m (width of the lower covering portion), a height of 3 m, and a depth of 5 0.3 m (volume about 19 m ³ ). The covering part was formed from a satin-made polyolefin film for agricultural use (CI Kasei Co., Ltd.).
In the greenhouse, the growing rooms are arranged in a row.

The carbon dioxide concentration and light intensity in the greenhouse are the CO ₂ sensor (Visala, model number: GMW22, and LI-COR, model number: LI-640), light intensity meter (Eihiro Seiki Co., Ltd.) It was measured by a company, model number: ML-020VM).
The air temperature and relative humidity were calculated from these values by measuring the dry bulb temperature and wet bulb temperature using two copper-constantan thermocouples (T-type thermocouples) that were made by themselves.
Similarly, the carbon dioxide concentration, light intensity, air temperature, and relative humidity in the growth room were also measured using the same apparatus and method as those in the above-mentioned greenhouse.

In addition, for carbon dioxide application to the growth chamber, piping in which nozzles were installed at intervals of 1.5 m was provided in the growth chamber, and carbon dioxide was ejected from the nozzle and supplied.
In addition, the carbon dioxide gas was supplied to piping using the carbon dioxide cylinder. The carbon dioxide gas supply capacity of this carbon dioxide cylinder is 200 kg CO ₂ / ha / h at the maximum, and about 1.5 L / min. Supplied with.

(1) Ventilation characteristics of the growth room First, the ventilation characteristics of the growth room were confirmed by the CO ₂ tracer gas method. That is, a large amount of carbon dioxide gas was supplied into the growth chamber, and the time until the carbon dioxide gas concentration in the growth chamber reached 3000 ppm to 1500 ppm was confirmed. The reason why the carbon dioxide concentration for measuring the number of ventilations was changed from 3000 ppm to 1500 ppm is to reduce the influence of respiration and photosynthesis of plants in the growing room.
As shown in FIG. 4, when the measurement was performed twice, it took about 230 seconds for the first time and about 220 seconds for the second time. From this result, the ventilation frequency per hour in the growth room was calculated. When calculated, it was about 11 times per hour.
From the above results, it was confirmed that in the plant growth facility of the present invention, the number of ventilations in the growth room was less than the number of ventilations in the greenhouse.

(2) Carbon dioxide concentration maintenance function in the growth room Next, the carbon dioxide concentration maintenance function of the growth room was confirmed.
In the experiment, carbon dioxide was supplied into the growth chamber at a flow rate of 1.5 L / min. With the ventilation window of the greenhouse fully opened, and the change over time in the carbon dioxide concentration in the air in the greenhouse and the growth chamber was measured.
As shown in FIG. 5 (d) and FIG. 6 (h), in the growth chamber, the carbon dioxide concentration increases approximately immediately after the carbon dioxide supply is started until the carbon dioxide supply is stopped. It is maintained at 1000ppm or more.
On the other hand, in the greenhouse air, the carbon dioxide concentration does not change even during the start of the supply of carbon dioxide into the growth chamber, and is almost constant during the measurement period.
From the above results, it was confirmed that the plant growth facility of the present invention can maintain a high carbon dioxide concentration in the growth chamber even if the amount of carbon dioxide supplied is small, regardless of the state of the greenhouse (ventilation, etc.).

(3) Temperature maintenance function Next, the temperature maintenance function of the breeding room was confirmed.
In the experiment, the temperature of the growing room on a sunny day in summer was compared with the temperature of the greenhouse.
The amount of heat supplied to the greenhouse by solar radiation was 3 MJ / m ² / h, and the amount of solar radiation incident on the growth room was 1.5 MJ / m ² / h. The outdoor temperature on this day was 30 ° C. and the humidity was 45%.

  The temperature and humidity of the growth room and the greenhouse were 32 ° C. and the humidity was 50%, and the temperature inside the growth room was 32 ° C. and the humidity was 90%. That is, it was confirmed that the temperature of the growing room was maintained at the same level as the temperature of the greenhouse, and at the same time the humidity of the air in the growing room was higher than the humidity of the air in the greenhouse.

Therefore, assuming that ventilation was performed 11 times per hour and calculating the heat balance of the growth room, the amount of heat supplied to the growth room was about 4.1 MJ / m ² / h, and ventilation was conducted from the growth room. The amount of heat exhausted by this is 3.8 MJ / m ² / h.
Considering that the humidity of the air in the growing room is 90%, the amount of water transpiration from the plant is 0.45 kg / h, and the heat of vaporization is 1.1 MJ / m ² / h.
Then, the total amount of heat exhausted from the growth room by ventilation and the heat of vaporization (about 4.9 MJ / m ² / h) almost coincides with the amount of heat supplied to the growth room.

  From the above results, in the plant growing facility of the present invention, if the humidity of the air in the growing room is higher than the humidity of the air in the greenhouse, the amount of heat supplied to the growing room even on a sunny day in summer It was confirmed that the amount of heat discharged from the growing room can be made substantially the same, and the temperature of the growing room can be maintained in the same state as the temperature of the greenhouse or the outdoor temperature.

  5 and 6, when the relative humidity of the air in the growth room and the greenhouse and the temperature change of the growth room and the greenhouse are confirmed over time, the relative temperature of the air in the growth room during the daytime in both winter and summer. Humidity is higher than the relative humidity of the air in the greenhouse, and the difference between the temperature in the growth room and the temperature in the greenhouse is suppressed to 5 degrees or less. From this result, it can be confirmed that if the humidity of the air in the growth room is higher than the humidity of the air in the greenhouse, the temperature maintenance function of the growth room functions effectively.

(4) Photosynthetic properties of plants under high carbon dioxide concentration conditions Next, changes in the photosynthetic properties of leaves when plants were grown under high carbon dioxide concentration conditions were confirmed.
In the experiment, a portable photosynthetic transpiration measuring device (manufactured by LI-COR) was used for tomatoes (CO ₂ district) to which carbon dioxide was applied for 2 weeks and tomato leaves (control zone) to which carbon dioxide was not applied. The photosynthesis ability (photo-photosynthesis curve) was measured using an apparatus model number: LI-6400.
In addition, the tomatoes in the CO ₂ section were cultivated and applied with carbon dioxide in the plant growing facility of the present invention. The variety of tomato used is Tomimaru Mucho.
Moreover, the carbon dioxide concentration at the time of photo-photosynthesis curve measurement was 400 ppm and 1500 ppm.

As shown in FIG. 7, under high carbon dioxide concentration conditions (assuming carbon dioxide application: 1500 ppm), it can be seen that the photosynthesis capacity of the CO ₂ section is significantly larger than that of the control section. .
From the above results, by applying carbon dioxide and continuously growing plants under high carbon dioxide concentration conditions, leaves that can exhibit higher photosynthetic ability under high carbon dioxide concentration conditions are formed. Was confirmed.

  The plant growing facility of the present invention is suitable for a plant factory for growing plants such as tomato, cucumber, eggplant, and paprika.

1 Plant Growing Facility 2 Greenhouse 10 Growing Room 10h Space 11 Covering Section

Claims (4)

A greenhouse that uses sunlight,
A growth room provided in the greenhouse for growing the plant in a state of containing the plant,
The training room
A covering portion made of a light-transmitting member provided to surround the plant;
Carbon dioxide supply means for supplying carbon dioxide into the coating part, disposed in the coating part,
In the covering portion,
A ventilation part is provided for ventilating the air in the covering part and the air in the greenhouse,
The covering portion is
A plant-growing facility characterized in that the humidity of the air in the covering part is maintained higher than the humidity of the air in the greenhouse. The ventilation section is
The plant growth facility according to claim 1, wherein the number of ventilations in the growth room is formed to be less than the number of ventilations in the greenhouse. The plant growing facility according to claim 1 or 2, wherein the light transmissive member forming the covering portion has a structure capable of scattering the light irradiated to the covering portion. The plant growing facility according to claim 1, wherein water spraying means for spraying water droplets on the outer surface of the covering portion is provided in the greenhouse.